気体、圧力、体積

Squeezing a gas

• Push a bicycle pump with your finger over the end and you can feel the gas push back harder as you squeeze.
• For a fixed amount of gas at constant temperature, pressure 压强 and volume 体积 are linked.

Pressure from particles

• Gas pressure comes from particles colliding with the container walls.
• More frequent or harder collisions mean higher pressure.

A heated gas: faster particles spread out and take up more space

Pressure and volume

• Squeeze a gas into a smaller volume and the particles hit the walls more often → higher pressure.
• Pressure × volume = constant (at fixed temperature) — this is Boyle's law 玻意耳定律.

As volume decreases, pressure increases — their product stays constant.

Using the relationship

• If you halve the volume, the pressure doubles.
• So p₁V₁ = p₂V₂ lets you find a new pressure or volume.

You've got it